﻿// <file>
//     <copyright see="prj:///doc/copyright.txt"/>
//     <license see="prj:///doc/license.txt"/>
//     <owner name="Mike Krüger" email="mike@icsharpcode.net"/>
//     <version>$Revision$</version>
// </file>

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Windows.Forms;
using System.Xml;
using System.Xml.Schema;

namespace ICSharpCode.TextEditor.Document
{
    public static class HighlightingDefinitionParser
    {
        public static DefaultHighlightingStrategy Parse(SyntaxMode syntaxMode, XmlReader xmlReader)
        {
            return Parse(null, syntaxMode, xmlReader);
        }

        public static DefaultHighlightingStrategy Parse(DefaultHighlightingStrategy highlighter, SyntaxMode syntaxMode, XmlReader xmlReader)
        {
            if (syntaxMode == null)
                throw new ArgumentNullException("syntaxMode");
            if (xmlReader == null)
                throw new ArgumentNullException("xmlTextReader");
            try
            {
                List<ValidationEventArgs> errors = null;
                XmlReaderSettings settings = new XmlReaderSettings();
                //TODO-texteditor-ch was: Stream schemaStream = typeof(HighlightingDefinitionParser).Assembly.GetManifestResourceStream("ICSharpCode.TextEditor.Resources.Mode.xsd");
                string schemaStreamFile = Path.Combine("SyntaxDefinition", "Mode.xsd"); // TODO-texteditor-ch this dir needs to come from?
                Stream schemaStream = File.OpenRead(schemaStreamFile);
                settings.Schemas.Add("", new XmlTextReader(schemaStream));
                settings.Schemas.ValidationEventHandler += delegate(object sender, ValidationEventArgs args)
                {
                    if (errors == null)
                    {
                        errors = new List<ValidationEventArgs>();
                    }
                    errors.Add(args);
                };
                settings.ValidationType = ValidationType.Schema;
                XmlReader validatingReader = XmlReader.Create(xmlReader, settings);

                XmlDocument doc = new XmlDocument();
                doc.Load(validatingReader);

                if (highlighter == null)
                    highlighter = new DefaultHighlightingStrategy(doc.DocumentElement.Attributes["name"].InnerText);

                if (doc.DocumentElement.HasAttribute("extends"))
                {
                    KeyValuePair<SyntaxMode, ISyntaxModeFileProvider> entry = HighlightingManager.Manager.FindHighlighterEntry(doc.DocumentElement.GetAttribute("extends"));
                    if (entry.Key == null)
                    {
                        throw new HighlightingDefinitionInvalidException("Cannot find referenced highlighting source " + doc.DocumentElement.GetAttribute("extends"));
                    }
                    else
                    {
                        highlighter = Parse(highlighter, entry.Key, entry.Value.GetSyntaxModeFile(entry.Key));
                        if (highlighter == null) return null;
                    }
                }
                if (doc.DocumentElement.HasAttribute("extensions"))
                {
                    highlighter.Extensions = doc.DocumentElement.GetAttribute("extensions").Split(new char[] { ';', '|' });
                }

                XmlElement environment = doc.DocumentElement["Environment"];
                if (environment != null)
                {
                    foreach (XmlNode node in environment.ChildNodes)
                    {
                        if (node is XmlElement)
                        {
                            XmlElement el = (XmlElement)node;
                            if (el.Name == "Custom")
                            {
                                highlighter.SetColorFor(el.GetAttribute("name"), el.HasAttribute("bgcolor") ? new HighlightBackground(el) : new HighlightColor(el));
                            }
                            else
                            {
                                highlighter.SetColorFor(el.Name, el.HasAttribute("bgcolor") ? new HighlightBackground(el) : new HighlightColor(el));
                            }
                        }
                    }
                }

                // parse properties
                if (doc.DocumentElement["Properties"]!= null)
                {
                    foreach (XmlElement propertyElement in doc.DocumentElement["Properties"].ChildNodes)
                    {
                        highlighter.Properties[propertyElement.Attributes["name"].InnerText] =  propertyElement.Attributes["value"].InnerText;
                    }
                }

                if (doc.DocumentElement["Digits"]!= null)
                {
                    highlighter.DigitColor = new HighlightColor(doc.DocumentElement["Digits"]);
                }

                XmlNodeList nodes = doc.DocumentElement.GetElementsByTagName("RuleSet");
                foreach (XmlElement element in nodes)
                {
                    highlighter.AddRuleSet(new HighlightRuleSet(element));
                }

                xmlReader.Close();

                if (errors != null)
                {
                    StringBuilder msg = new StringBuilder();
                    foreach (ValidationEventArgs args in errors)
                    {
                        msg.AppendLine(args.Message);
                    }
                    throw new HighlightingDefinitionInvalidException(msg.ToString());
                }
                else
                {
                    return highlighter;
                }
            }
            catch (Exception e)
            {
                throw new HighlightingDefinitionInvalidException("Could not load mode definition file '" + syntaxMode.FileName + "'.\n", e);
            }
        }
    }
}
